Figure 6: Network Terminal Block and Wiring
Connections
4. If a dial application is required, connect an external
modem to the RS232C port you wish to use.
5. If a direct connect application is required, connect the
appropriate computer cable to the RS232C port you
wish to use.
6. Connect the 24 VAC supply power wires from the
transformer to the removable 3-terminal plug as
shown in
. The middle terminal is not used.
Figure 7: 24 VAC Supply Power Wiring
Note:
Power supply wire colors may be different on
transformers not manufactured by
Johnson
Controls®
. Follow the transformer manufacturer’s
instructions or the project installation drawings.
Note:
When connecting 24 VAC power to the NCMs and
field devices on the network, be consistent so that
transformer phasing is uniform across the devices.
Powering devices with uniform 24 VAC supply
power phasing reduces noise, interference, and
ground loop problems. The NCM does not require
an earth ground connection.
Wiring Considerations and Guidelines for Network Integrations
Table 1: Guidelines for N2 Network Topology
Rules/Maximums Allowed
Category
One N2 trunk per
NCM
General
Only daisy-chained devices (with maximum stub length of 3 m [10 ft] to any device)
100 devices per NCM (60 to 200 TC-9100s) 50 devices per repeater with two
repeaters cascaded
Number of N2 Devices Supported
1,500 m (5,000 ft) twisted pair cable without a repeater
Cable Length and Type
4,500 m (15,000 ft) twisted pair cable from an NCM and the farthest N2 device
(three segments of 1,500 m [5,000 ft] each, separated by repeaters)
2,000 m (6,600 ft) between two fiber modems
Solid or stranded 18 AWG recommended (24 AWG twisted pair or larger is
acceptable)
Cable Wire Type and Size
Two N2 devices with EOL switches in the ON position, one at each end of each
N2 Bus segment
N2
EOL
Terminations
Table 2: Guidelines for
L
ON
W
ORKS
Network Bus Topology
Maximum Segment Length
with FTT10 and/or LPT10
Devices
Maximum Segment Length with FTT10
Devices Only
Cable Type
2,200 m (7,200 ft)
2,700 m (8,850 ft)
Belden®
85102
2,200 m (7,200 ft)
2,700 m (8,850 ft)
Belden 8471
6
NCM45x0-2 Series Network Control Module Installation Instructions
